Many different types of data storage systems exist and are currently being used to store and access various types of data media, such as optical disks and magnetic tape cartridges to name a few, so that data may be read from and/or written to the data media. Typically, data storage systems include many media storage devices for storing a group of data media, one or more data exchange devices for reading from and/or writing to the data media, and a media handling device for transferring the data media between the media storage devices and the data exchange devices. A typical example of a data storage system is disclosed in U.S. patent application Ser. No. 09/045,134, entitled “Multi-Plane Translating Cartridge Handling System,” now U.S. Pat. No. 6,025,972, issued on Feb. 15, 2000, which is hereby incorporated by reference in its entirety.
The data media employed by data storage systems may be any of a variety of types of machine-readable devices capable of storing data, having the data read from the device by a data exchange device, and/or having the data written to the device by the data exchange devices. For instance, the data media may be a magnetic disk or tape, such as a digital linear tape (DLT) or an optical disk, such as a compact disc (CD) and a digital video disc (DVD). Depending on the type of data media employed by the data storage system, any of a variety of data exchange devices may be used.
The data exchange devices and the media storage devices are typically positioned at various locations around the media handling device so that the media handling device may access the data media stored in the media storage devices. Examples of media storage devices are disclosed in U.S. Pat. No. 6,042,205, issued on Mar. 28, 2002, entitled “Media Holding Device Incorporating A Media Locking Mechanism” and U.S. Pat. application Ser. No. 09/257,322, entitled “Data Cartridge Exchange Apparatus,” which are hereby incorporated by reference in their entirety.
In many data storage systems, the media storage devices are arranged in a plurality of vertical stacks. Such data storage systems typically include a lift assembly engaged with, and for, moving the media handling device to access the data media arranged in the vertical stacks.
Data storage systems are usually connected to a host computer system that may access or store data on the data media. For example, if the host computer issues a request for data contained on a particular data medium, a control system associated with the data storage system may engage a positioning system to move the media handling system adjacent the desired data medium. The media handling system may then remove the data medium from the media storage device and transport it to the data exchange device. When properly positioned adjacent the data exchange device, the media handling system may insert the data medium in the data exchange device so that the host computer may access the data stored on the data medium.
It is often necessary and desirable for an operator or service personnel to periodically access the data media contained within the data storage system. Therefore, data storage systems may be configured in a variety of ways to enable the operator to access the data media. For example, as disclosed in U.S. Pat. No. 6,042,205, the media storage devices may implemented within a data media exchange apparatus providing an extendable drawer that can be pulled open to allow the operator to access the data media stored in the data storage system. However, present data systems have several disadvantages. For example, most data storage systems store a large number of data media and therefore require numerous media storage devices. In practice it is desirable to provide a security mechanism, such as a locking device, so that an operator does not try to access a particular data media exchange apparatus while it is simultaneously being accessed by the data storage system. Thus, such data storage systems include a separate locking mechanism for each data media exchange apparatus to be accessed by the operator. The data storage systems may also include a separate sensing means for monitoring the locking mechanisms. As the size of data storage systems have increased to include a larger number of data media, and consequently a larger number of access points, the cost of including the separate locking and monitoring mechanisms has also increased.